Altitude
Sensors
Global Positioning Systems
See also:
Adept
Altimeters for rockets using a pressure sensor.
http://www.devrs.com/
An Adept Rocketry PIC-based (16c54) model rocket schematic is now online that was reverse-engineered back in 1993. They now appear to be out-of-business. Click on PICs
http://www.novasensor.com/
http://mot-sps.com/products/sensors/
http://www.geocities.com/rocketroos/picalt_release.htm
http://www.geocities.com/SiliconValley/Orchard/6633/altimeter.html
http://www.rocket-roar.com/rap/alt.html